2018 Lexus GS450h check engine

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GS450h_OM_OM30G62U_(U)
6-3. Do-it-yourself maintenance
The coolant level is satisfactory if it is between the “FULL” and “LOW” lines on
the reservoir when the hybrid system is cold.
■Engine coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( →P. 461)
■Power control unit coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( →P. 461)
■Coolant selection
Only use “Toyota Super Long Life Coolant” or a similar high quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid
organic acid technology.
U.S.A.:
“Toyota Super Long Life Coolant” is a mixt ure of 50% coolant and 50% deionized water.
(Minimum temperature: -31 °F [-35 °C])
Canada:
“Toyota Super Long Life Cool ant” is a mixture of 55% coolant and 45% deionized water.
(Minimum temperature: -44° F [-42°C])
For more details about coolant, contact your Lexus dealer.
■If the coolant level drops within a short time of replenishing
Visually check the radiator, hoses, engine/power control unit coolant reservoir caps,
drain cock and water pump.
If you cannot find a leak, have your Lexus de aler test the cap and check for leaks in the
cooling system.
Coolant
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GS450h_OM_OM30G62U_(U)
3596-3. Do-it-yourself maintenance
6
Maintenance and care
Check the radiator and condenser and clear away any foreign objects.
If either of the above parts is extremely dirty or you are not sure of their condi-
tion, have your vehicle inspected by your Lexus dealer.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control un it coolant reservoir caps or the coolant
inlet cap. ( →P. 465)
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing serious injuries, such as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor straight antifreeze. The correct mixture of water and
antifreeze must be used to provide proper lubrication, corrosion protection and cool-
ing. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it from damaging parts or paint.
Radiator and condenser
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause serious injuries,
such as burns.

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GS450h_OM_OM30G62U_(U)
6-3. Do-it-yourself maintenance
Checking and replacing fuses
Turn the power switch off.
Open the fuse box cover.
Engine compartment
Remove the engine compartment
cover (→P. 354) and remove all of
the clips.
Push the tabs on either side to
detach the lock and lift the lid off
while pulling the lock plate.
When installing the lid, check that the
lock plate and the tabs on either side
are connected correctly.
If any of the electrical components do not operate, a fuse may have blown. If
this happens, check and repl ace the fuses as necessary.
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GS450h_OM_OM30G62U_(U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Light bulbs
Check the wattage of the light bulb to be replaced. ( →P. 480)
→ P. 354
Front turn signal light (vehicles with single-beam headlights)
You may replace the following bulbs by yo urself. The difficulty level of replace-
ment varies depending on the bulb. If necessary bulb replacement seems diffi-
cult to perform, contact your Lexus dealer.
For more information about replacing other light bulbs, contact your Lexus
dealer.
Preparing for light bulb replacement
Removing the engine compartment covers
Bulb locations
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4287-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
Indicates a malfunction in the brake override systemA buzzer also sounds.
→ Have the vehicle inspecte d by your Lexus dealer
immediately.
Indicates that engine oil level is low
This message may ap pear if the vehicle is stopped on a
slope. Move the vehicle to a level surface and check to
see if the message disappears.
A buzzer also sounds.
→ Check the level of engine oil, and add if necessary.
Indicates that the hybrid system has overheated
This message may be disp layed when driving under
severe operating conditions. (For example, when driv-
ing up a long steep hill.)
A buzzer also sounds.
→ Stop and check. ( →P. 461)
Indicates a malfunction in:
• The Automatic High Beam system (if equipped);
• The AFS (Adaptive Front-lighting System) (if equipped); or
• The LED headlight system
A buzzer also sounds.
→ Have the vehicle inspected by your Lexus dealer.
Warning messageDetails/Actions
(Flashes)

4307-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
Indicates that the tire position information cannot be rec-
ognized
→Drive for a short while an d check if the display
updates.
If the radio wave conditions improve, the display
may return to normal. If th e tire pressure is still not
displayed after driving for several minutes, stop the
vehicle in a safe place, turn the power switch off
then on again, and start driv ing. If the tire pressure is
still not displayed even after repeating this process
several times, have the vehicle inspected at your
Lexus dealer.
Indicates that the washer fluid level is low
→ Add washer fluid.
Except F SPORT models: Indicates that remaining fuel is
approximately 2.6 gal. (10.0 L, 2.2 Imp.gal.) or less
F SPORT models: Indicates remaining fuel is approxi-
mately 2.6 gal. (9.9 L, 2.2 Imp.gal.) or less
→ Refuel the vehicle.
Indicates that the outside temperature is approximately
37° F (3 °C) or lower
A buzzer also sounds.
→ Drive carefully, as the road may be icy.
Indicates that the power oil is scheduled to be changed
→Check the engine oil and change if necessary. After
changing the engine oil, the oil change system
should be reset. ( →P. 355)
(The indicator will not work properly unless the oil
maintenance data has been reset.)
Warning messageDetails/Actions

4317-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
7
When trouble arises
*: Refer to the separate “Scheduled Maintenance” or “Owner’s Manual Supplement”
for the maintenance interval applicable to your vehicle.
(U.S.A. only)
Indicates that all maintenance according to the driven
distance on the maintenance schedule
* should be per-
formed soon.
Comes on approximately 4500 miles (7200 km)
after the message has been reset.
→ If necessary, perform maintenance.
Indicates that the engine o il and oil filter should be
changed
→ Have the engine oil and oil filter checked and/or
changed by your Lexus dealer. After changing the
engine oil, the oil change system should be reset.
( → P. 355)
(U.S.A. only)
Indicates that all maintenanc e is required to correspond
to the driven distance on the maintenance schedule
*.
Comes on approximately 5000 miles (8000 km)
after the message has been reset. (The message will
not display properly unless the message has been
reset.)
→ Perform the necessary maintenance. Please reset
the message after the maintenance is performed.
(→ P. 344)
(If equipped)
Indicates that the Automati c High Beam switch was
pressed while the low beams were on
→ Turn the high beam headlights on before pressing
the Automatic High Beam switch.
(If equipped)
Indicates that, since the VSC (Vehicle Stability Control)
system was turned off, the pre-collision braking and pre-
collision brake assist are stopped (The pre-collision
warning function will be operational)
→ Turn the VSC on. ( →P. 271)
Warning messageDetails/Actions

4487-2. Steps to take in an emergency
GS450h_OM_OM30G62U_(U)
Firmly tighten each wheel nut two or
three times in the order shown in the
illustration.
Tightening torque:
76 ft•lbf (103 N•m, 10.5 kgf•m)
Stow the flat tire, tire jack and all tools.
■The compact spare tire
●The compact spare tire is identified by the label “TEMPORARY USE ONLY” on the
tire sidewall.
●Use the compact spare tire temporarily, and only in an emergency.
●Make sure to check the tire inflation pressure of the compact spare tire. (→P. 477)
■When using the compact spare tire
As the compact spare tire is not equipped wi th a tire pressure warning valve and trans-
mitter, low inflation pressure of the spare tire will not be indicated by the tire pressure
warning system. Also, if you replace the compact spare tire after the tire pressure warn-
ing light comes on, the light remains on.
■When the compact spare tire is equipped
The vehicle may become lower when driving with the compact spare tire compared to
when driving with standard tires.
■If you have a flat rear tire on a road covered with snow or ice
Install the compact spare tire on one of the front wheels of the vehicle. Perform the fol-
lowing steps and fit tire chains to the rear tires:
Replace a front tire with the compact spare tire.
Replace the flat rear tire with the tire removed from the front of the vehicle.
Fit tire chains to the rear tires.
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WARNING
■When using the compact spare tire
●Remember that the compact spare tire provid ed is specifically designed for use with
your vehicle. Do not use your comp act spare tire on another vehicle.
●Do not use more than one compact spare tire simultaneously.
●Replace the compact spare tire with a standard tire as soon as possible.
●Avoid sudden acceleration, abrupt steering, sudden braking and shifting operations
that cause sudden engine braking.